Loop Diuretics Cause Hypokalemia?
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Kidney, Renal Tubule – Dilation
Kidney, Renal Tubule – Dilation Figure Legend: Figure 1 Kidney, Renal tubule - Dilation in a male B6C3F1 mouse from a chronic study. Dilated tubules are noted as tracts running through the cortex and outer medulla. Figure 2 Kidney, Renal tubule - Dilation in a male F344/N rat from a chronic study. Tubule dilation is present throughout the outer stripe of the outer medulla, extending into the cortex. Figure 3 Kidney, Renal tubule - Dilation in a male B6C3F1 mouse from a chronic study. Slight tubule dilation is associated with degeneration and necrosis. Figure 4 Kidney, Renal tubule - Dilation in a male F344/N rat from a chronic study. Tubule dilation is associated with chronic progressive nephropathy. Comment: Renal tubule dilation may occur anywhere along the nephron or collecting duct system. It may occur in focal areas or as tracts running along the entire length of kidney sections (Figure 1). 1 Kidney, Renal Tubule – Dilation Renal tubule dilation may occur from xenobiotic administration, secondary mechanisms, or an unknown pathogenesis (see Kidney – Nephropathy, Obstructive (Figure 2). Dilation may result from direct toxic injury to the tubule epithelium interfering with absorption and secretion (Figure 3). It may also occur secondary to renal ischemia or from prolonged diuresis related to drug administration. Secondary mechanisms of tubule dilation may result from lower urinary tract obstruction, the deposition of tubule crystals, interstitial inflammation and/or fibrosis, and chronic progressive nephropathy (Figure 4). A few dilated tubules may be regarded as normal histologic variation. Recommendation: Renal tubule dilation should be diagnosed and given a severity grade. The location of tubule dilation should be included in the diagnosis as a site modifier. -
Excretory Products and Their Elimination
290 BIOLOGY CHAPTER 19 EXCRETORY PRODUCTS AND THEIR ELIMINATION 19.1 Human Animals accumulate ammonia, urea, uric acid, carbon dioxide, water Excretory and ions like Na+, K+, Cl–, phosphate, sulphate, etc., either by metabolic System activities or by other means like excess ingestion. These substances have to be removed totally or partially. In this chapter, you will learn the 19.2 Urine Formation mechanisms of elimination of these substances with special emphasis on 19.3 Function of the common nitrogenous wastes. Ammonia, urea and uric acid are the major Tubules forms of nitrogenous wastes excreted by the animals. Ammonia is the most toxic form and requires large amount of water for its elimination, 19.4 Mechanism of whereas uric acid, being the least toxic, can be removed with a minimum Concentration of loss of water. the Filtrate The process of excreting ammonia is Ammonotelism. Many bony fishes, 19.5 Regulation of aquatic amphibians and aquatic insects are ammonotelic in nature. Kidney Function Ammonia, as it is readily soluble, is generally excreted by diffusion across 19.6 Micturition body surfaces or through gill surfaces (in fish) as ammonium ions. Kidneys do not play any significant role in its removal. Terrestrial adaptation 19.7 Role of other necessitated the production of lesser toxic nitrogenous wastes like urea Organs in and uric acid for conservation of water. Mammals, many terrestrial Excretion amphibians and marine fishes mainly excrete urea and are called ureotelic 19.8 Disorders of the animals. Ammonia produced by metabolism is converted into urea in the Excretory liver of these animals and released into the blood which is filtered and System excreted out by the kidneys. -
Renal Aquaporins
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Kidney International, Vol. 49 (1996), pp.1712—1717 Renal aquaporins MARK A. KNEPPER, JAMES B. WADE, JAMES TERRIS, CAROLYN A. ECELBARGER, DAVID MARPLES, BEATRICE MANDON, CHUNG-LIN CHOU, B.K. KISHORE, and SØREN NIELSEN Laborato,y of Kidney and Electrolyte Metabolism, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Matyland, USA; Department of Cell Biology, Institute of Anatomy, University of Aarhus, Aarhus, Denmark; and Department of Physiology, University of Maiyland College of Medicine, Baltimore, and Department of Physiology, Unifornied Services University of the Health Sciences, Bethesda, Maiyland, USA Renal aquaporins. Aquaporins (AQPs) are a newly recognized family of gate the localization and regulation of the four renal aquaporins transmembrane proteins that function as molecular water channels. At (AQP1, AQP2, AQP3 and AQP4). least four aquaporins are expressed in the kidney where they mediate Urine is concentrated as a result of the combined function of rapid water transport across water-permeable epithelia and play critical roles in urinary concentrating and diluting processes. AQP1 is constitu- the loop of Henle, which generates a high osmolality in the renal tively expressed at extremely high levels in the proximal tubule and medulla by countercurrent multiplication, and the collecting duct, descending limb of Henle's loop. AQP2, -3 and -4 are expressed predom- which, in the presence of the antidiuretic hormone vasopressin, inantly in the collecting duct system. AQP2 is the predominant water permits osmotic equilibration between the urine and the hyper- channel in the apical plasma membrane and AQP3 and -4arefound in the basolateral plasma membrane. -
Kidney Function • Filtration • Reabsorption • Secretion • Excretion • Micturition
About This Chapter • Functions of the kidneys • Anatomy of the urinary system • Overview of kidney function • Filtration • Reabsorption • Secretion • Excretion • Micturition © 2016 Pearson Education, Inc. Functions of the Kidneys • Regulation of extracellular fluid volume and blood pressure • Regulation of osmolarity • Maintenance of ion balance • Homeostatic regulation of pH • Excretion of wastes • Production of hormones © 2016 Pearson Education, Inc. Anatomy of the Urinary System • Kidneys, ureters, bladder, and urethra • Kidneys – Bean-shaped organ – Cortex and medulla © 2016 Pearson Education, Inc. Anatomy of the Urinary System • Functional unit is the nephron – Glomerulus in the Bowman’s capsule – Proximal tubule – The loop of Henle • Descending limb and ascending limb twisted between arterioles forming the juxtaglomerular apparatus – Distal tubule – Collecting ducts © 2016 Pearson Education, Inc. Figure 19.1b Anatomy summary The kidneys are located retroperitoneally at the level of the lower ribs. Inferior Diaphragm vena cava Aorta Left adrenal gland Left kidney Right kidney Renal artery Renal vein Ureter Peritoneum Urinary Rectum (cut) bladder (cut) © 2016 Pearson Education, Inc. Figure 19.1c Anatomy summary © 2016 Pearson Education, Inc. Figure 19.1d Anatomy summary © 2016 Pearson Education, Inc. Figure 19.1f-h Anatomy summary Some nephrons dip deep into the medulla. One nephron has two arterioles and two sets of capillaries that form a portal system. Efferent arteriole Arterioles Peritubular Juxtaglomerular capillaries The cortex apparatus contains all Bowman’s Nephrons Afferent capsules, arteriole Glomerulus proximal Juxtamedullary nephron and distal (capillaries) with vasa recta tubules. Peritubular capillaries Glomerulus The medulla contains loops of Henle and Vasa recta collecting ducts. Collecting duct Loop of Henle © 2016 Pearson Education, Inc. -
Embryology of the Kidney Rizaldy Paz Scott | Yoshiro Maezawa | Jordan Kreidberg | Susan E
1 Embryology of the Kidney Rizaldy Paz Scott | Yoshiro Maezawa | Jordan Kreidberg | Susan E. Quaggin CHAPTER OUTLINE MAMMALIAN KIDNEY DEVELOPMENT, 2 MOLECULAR GENETICS OF MODEL SYSTEMS TO STUDY KIDNEY NEPHROGENESIS, 22 DEVELOPMENT, 8 GENETIC ANALYSIS OF MAMMALIAN KIDNEY DEVELOPMENT, 15 KEY POINTS • The development of the kidney relies on reciprocal signaling and inductive interactions between neighboring cells. • Epithelial cells that comprise the tubular structures of the kidney are derived from two distinct cell lineages: the ureteric epithelia lineage that branches and gives rise to collecting ducts and the nephrogenic mesenchyme lineage that undergoes mesenchyme to epithelial transition to form connecting tubules, distal tubules, the loop of Henle, proximal tubules, parietal epithelial cells, and podocytes. • Nephrogenesis and nephron endowment requires an epigenetically regulated balance between nephron progenitor self-renewal and epithelial differentiation. • The timing of incorporation of nephron progenitor cells into nascent nephrons predicts their positional identity within the highly patterned mature nephron. • Stromal cells and their derivatives coregulate ureteric branching morphogenesis, nephrogenesis, and vascular development. • Endothelial cells track the development of the ureteric epithelia and establish the renal vasculature through a combination of vasculogenic and angiogenic processes. • Collecting duct epithelia have an inherent plasticity enabling them to switch between principal and intercalated cell identities. MAMMALIAN KIDNEY DEVELOPMENT The filtration function of the kidneys is accomplished by basic units called nephrons (Fig. 1.1). Humans on average have 1 million nephrons per adult kidney but the range of ANATOMIC OVERVIEW OF THE 4 MAMMALIAN KIDNEY total nephrons is highly variable across human populations. Each mouse kidney may contain up to 12,000–16,000 nephrons The kidney is a sophisticated, highly vascularized organ that depending on the strain.5 This wide range in nephron number plays a central role in overall body homeostasis. -
The Urinary System Dr
The urinary System Dr. Ali Ebneshahidi Functions of the Urinary System • Excretion – removal of waste material from the blood plasma and the disposal of this waste in the urine. • Elimination – removal of waste from other organ systems - from digestive system – undigested food, water, salt, ions, and drugs. + - from respiratory system – CO2,H , water, toxins. - from skin – water, NaCl, nitrogenous wastes (urea , uric acid, ammonia, creatinine). • Water balance -- kidney tubules regulate water reabsorption and urine concentration. • regulation of PH, volume, and composition of body fluids. • production of Erythropoietin for hematopoieseis, and renin for blood pressure regulation. Anatomy of the Urinary System Gross anatomy: • kidneys – a pair of bean – shaped organs located retroperitoneally, responsible for blood filtering and urine formation. • Renal capsule – a layer of fibrous connective tissue covering the kidneys. • Renal cortex – outer region of the kidneys where most nephrons is located. • Renal medulla – inner region of the kidneys where some nephrons is located, also where urine is collected to be excreted outward. • Renal calyx – duct – like sections of renal medulla for collecting urine from nephrons and direct urine into renal pelvis. • Renal pyramid – connective tissues in the renal medulla binding various structures together. • Renal pelvis – central urine collecting area of renal medulla. • Hilum (or hilus) – concave notch of kidneys where renal artery, renal vein, urethra, nerves, and lymphatic vessels converge. • Ureter – a tubule that transport urine (mainly by peristalsis) from the kidney to the urinary bladder. • Urinary bladder – a spherical storage organ that contains up to 400 ml of urine. • Urethra – a tubule that excretes urine out of the urinary bladder to the outside, through the urethral orifice. -
Kaplan USMLE Step 1 Prep: Distribution Ion Channel Protein in Kidney
Kaplan USMLE Step 1 prep: Distribution ion channel protein in kidney FEB 3, 2020 Staff News Writer If you’re preparing for the United States Medical Licensing Examination® (USMLE®) Step 1 exam, you might want to know which questions are most often missed by test-prep takers. Check out this example from Kaplan Medical, and read an expert explanation of the answer. Also check out all posts in this series. This month’s stumper An investigator is examining the distribution of an ion channel protein in the kidney. Slices of kidney tissue are incubated in a dilute solution of a specific antibody directed against the protein. The immunoperoxidase method is then used to localize the ion channel proteins. In one area, the investigator notes epithelial cells with a brush border that are positive for the ion channel protein. Which of the following areas is most likely to show these microscopic characteristics? A. Collecting duct. B. Descending thin limb of the loop of Henle. C. Distal convoluted tubule. D. Glomerulus. E. Proximal convoluted tubule. URL: https://www.ama-assn.org/residents-students/usmle/kaplan-usmle-step-1-prep-distribution-ion-channel-protein- kidney Copyright 1995 - 2021 American Medical Association. All rights reserved. The correct answer is E. Kaplan Medical explains why The proximal convoluted tubule (PCT) is the only portion of the renal tubule in which the epithelial cells have a "brush border." The brush border is composed of microvilli, which greatly increases apical membrane surface area and thereby enhances epithelial reabsorptive capacity. The PCT recovers almost 100% of filtered organic solutes (e.g., glucose, amino acids, proteins) and about 67% of electrolytes and water, amounting to about 120 L of the daily filtered load. -
L8-Urine Conc. [PDF]
The loop of Henle is referred to as countercurrent multiplier and vasa recta as countercurrent exchange systems in concentrating and diluting urine. Explain what happens to osmolarity of tubular fluid in the various segments of the loop of Henle when concentrated urine is being produced. Explain the factors that determine the ability of loop of Henle to make a concentrated medullary gradient. Differentiate between water diuresis and osmotic diuresis. Appreciate clinical correlates of diabetes mellitus and diabetes insipidus. Fluid intake The total body water Antidiuretic hormone is controled by : Renal excretion of water Hyperosmolar medullary Changes in the osmolarity of tubular fluid : interstitium 1 2 3 Low osmolarity The osmolarity High osmolarity because of active decrease as it goes up because of the transport of Na+ and because of the reabsorbation of water co-transport of K+ and reabsorption of NaCl Cl- 4 5 Low osmolarity because of High osmolarity because of reabsorption of NaCl , also reabsorption of water in reabsorption of water in present of ADH , present of ADH reabsorption of urea Mechanisms responsible for creation of hyperosmolar medulla: Active Co- Facilitated diffusion transport : transport : diffusion : of : Na+ ions out of the Only of small thick portion of the K+ , Cl- and other amounts of water ascending limb of ions out of the thick from the medullary the loop of henle portion of the Of urea from the tubules into the into the medullary ascending limb of inner medullary medullary interstitium the loop of henle collecting -
Morphology of the Kidney in a Nectarivorous Bird, the Anna's Hummingbird Calypte Anna
J. Zool., Lond. (1998) 244, 175±184 # 1998 The Zoological Society of London Printed in the United Kingdom Morphology of the kidney in a nectarivorous bird, the Anna's hummingbird Calypte anna G. Casotti1*, C. A. Beuchat2 and E. J. Braun3 1 Department of Biology, West Chester University, West Chester, PA, 19383, U.S.A. 2 Department of Biology, San Diego State University, San Diego, CA, 92182, U.S.A. 3 Department of Physiology, Arizona Health Sciences Center, University of Arizona, P.O. Box 245051, Tucson, AZ, 85724±5051, U.S.A. (Accepted 21 April 1997) Abstract The kidneys of Anna's hummingbird (Calypte anna) differ in several signi®cant ways from those of other birds that have been examined. The kidneys of this nectarivore contain very little medullary tissue; 90% of the total volume of the kidneys is cortical tissue, with medulla accounting for only an additional 2%. More than 99% of the nephrons are the so-called `reptilian type', which lack the loop of Henle. The few looped (`mammalian type') nephrons are incorporated into only a few medullary cones per kidney. The loopless nephrons are similar to those of other birds. However, the looped nephrons differ in that they lack the thin descending limb of the loop of Henle, which is found in other birds and is thought to play an important role in the countercurrent multiplier system in the avian kidney. Instead, the cells of the nephron segment following the pars recta of the proximal tubule resemble those of the thick ascending limb, with the large populations of mitochondria that are typical of transporting epithelia and no reduction in cell height. -
Urinary System
Urinary System Urinary System Urinary System - Overview: Major Functions: 1) Removal of organic waste products Kidney from fluids (excretion) 2) Discharge of waste products into the environment (elimination) 1 3) Regulation of the volume / [solute] / pH 3 of blood plasma Ureter HOWEVER, THE KIDNEY AIN’T JUST FOR PEE’IN… Urinary bladder • Regulation of blood volume / blood pressure (e.g., renin) • Regulation of red blood cell formation (i.e., erythropoietin) 2 • Metabolization of vitamin D to active form (Ca++ uptake) Urethra • Gluconeogenesis during prolonged fasting Marieb & Hoehn (Human Anatomy and Physiology, 8th ed.) – Figure 25.1 1 Urinary System Renal ptosis: Kidneys drop to lower position due Functional Anatomy - Kidney: to loss of perirenal fat Located in the superior lumbar “Bar of soap” region 12 cm x 6 cm x 3 cm 150 g / kidney Layers of Supportive Tissue: Renal fascia: Peritoneal cavity Outer layer of dense fibrous connective tissue; anchors kidney in place Perirenal fat capsule: Fatty mass surrounding kidney; cushions kidney against blows Fibrous capsule: Transparent capsule on kidney; prevents infection of kidney from local tissues Kidneys are located retroperitoneal Marieb & Hoehn (Human Anatomy and Physiology, 8th ed.) – Figure 25.2 Urinary System Functional Anatomy - Kidney: Pyelonephritis: Inflammation of the kidney Pyramids appear striped due to parallel arrangement of capillaries / collecting tubes Renal cortex Renal medulla Renal pyramids Renal papilla Renal columns Renal hilum Renal pelvis • Entrance for blood vessels -
Function of Thin Loops of Henle
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Kidney International, Vol. 31(1987), pp. 565—5 79 FUNCTION OF THE RENAL TUBULE Function of thin loops of Henle MASASHI IMAI, JuNIcHI TANIGUCHI, and KAORU TABEI Department of Pharmacology, National Cardiovascular Center Research Institute, Osaka 565 and Department of Cardiology, Jichi Medical School, Tochigi 329-04, Japan The existence of a steep osmotic gradient in the renalexplains the role of urea. The purpose of this communication is medullary interstitium is the most critical in the formation ofto review the transport properties of the thin segments of concentrated urine [1]. The architectural organization of theHenle's loop in an attempt to seek the possibility of generating renal tubules and blood vessels in the medulla constitutesa new idea for the countercurrent multiplication system without counterfiow systems which are essential for both generating andactive solute transport. maintaining high osmotic pressure of the renal medulla [2—4]. While it has been generally accepted that active NaCl transport Anatomical aspects in the thick ascending limb of Henle's loop plays the most Elegant morphologic studies reported in the last decade fundamental role in the operation of the countercurrent multi-[24—36] have disclosed that there are considerable inter- and plication system in the renal medulla, it is still a matter ofintranephron heterogeneity and species differences in the mor- considerable dispute whether the thin ascending limb (tAL) alsophology and architecture of the thin loop segments and blood has an active salt transport system to provide a "single effect"vessels in the renal medulla. -
Urea Permeability of Mammalian Inner Medullary Collecting Duct System and Papillary Surface Epithelium
Urea permeability of mammalian inner medullary collecting duct system and papillary surface epithelium. J M Sands, M A Knepper J Clin Invest. 1987;79(1):138-147. https://doi.org/10.1172/JCI112774. Research Article To compare passive urea transport across the inner medullary collecting ducts (IMCDs) and the papillary surface epithelium (PSE) of the kidney, two determinants of passive transport were measured, namely permeability coefficient and surface area. Urea permeability was measured in isolated perfused IMCDs dissected from carefully localized sites along the inner medullas of rats and rabbits. Mean permeability coefficients (X 10(-5) cm/s) in rat IMCDs were: outer third of inner medulla (IMCD1), 1.6 +/- 0.5; middle third (IMCD2), 46.6 +/- 10.5; and inner third (IMCD3), 39.1 +/- 3.6. Mean permeability coefficients in rabbit IMCDs were: IMCD1, 1.2 +/- 0.1; IMCD2, 11.6 +/- 2.8; and IMCD3, 13.1 +/- 1.8. The rabbit PSE was dissected free from the underlying renal inner medulla and was mounted in a specially designed chamber to measure its permeability to urea. The mean value was 1 X 10(-5) cm/s both in the absence and presence of vasopressin (10 nM). Morphometry of renal papillary cross sections revealed that the total surface area of IMCDs exceeds the total area of the PSE by 10-fold in the rat and threefold in the rabbit. We conclude: the IMCD displays axial heterogeneity with respect to urea permeability, with a high permeability only in its distal two-thirds; and because the urea permeability and surface area of the PSE are relatively small, passive transport across […] Find the latest version: https://jci.me/112774/pdf Urea Permeability of Mammalian Inner Medullary Collecting Duct System and Papillary Surface Epithelium Jeff M.